Electric field-induced effects on yeast cell wall permeabilization.

The permeability of the yeast cells (Saccharomyces cerevisiae) to lipophilic tetraphenylphosphonium cations (TPP(+) ) after their treatment with single square-shaped strong electric field pulses was analyzed. Pulsed electric fields (PEF) with durations from 5 to 150 µs and strengths from 0 to 10 kV/cm were applied to a standard electroporation cuvette filled with the appropriate buffer. The TPP(+) absorption process was analyzed using an ion selective microelectrode (ISE) and the plasma membrane permeability was determined by measurements obtained using a calcein blue dye release assay.

Evaluation of genotoxity and mutagenicity of DL-p-chlorophenylalanine, its methyl ester and some N-acyl derivatives.

DL-p-chlorophenylalanine (PCPA) and its derivatives were evaluated for genotoxic effects using Escherichia coli and Bacillus subtilis strains lacking various DNA-repair mechanisms in spottest and in suspension test. The mutagenic activity of studied compounds was determined by the Ames test. Reverse mutation test was performed with Salmonella typhimurium strains TA98, TA100, TA1535 and TA1537 without S9 mix.